1. Field of the Invention
This invention relates generally to an article handling apparatus and more particularly to a mechanism for separating and transporting sheets in a vertical orientation and for the synchronous delivery of single sheets in seriatim.
The apparatus of this invention is additionally concerned with a sheet feeding device compatible for use with high speed mail handling systems and especially adaptable for accommodating and processing a plurality of intermixed pieces of mail having various sizes and thicknesses.
2. Description of the Prior Art
Many of the prior art paper transport and feeding assemblies are designed for conveying uniform thickness sheets, data cards, blanks, coupons, documents or other similar materials and conventionally provide for the removal of sheets from either the top or bottom of a horizontally oriented stack as typically shown in U.S. Pat. No. 2,852,255.
Other known devices, such as those suitable for separation of pieces of mail having different thicknesses, generally utilize a resiliently movable separator or stripper which is either manually adjustable or otherwise yieldable with respect to a fixedly mounted conveyor to thereby provide compensation for the various sheet thicknesses. Such a device is shown, for example, in U.S. Pat. No. 1,955,066.
A disadvantage of these prior devices is that they do not effectively overcome the problems caused by adhesion of adjacent sheets particularly at high speed delivery. These previously known mail handling apparatus therefore do not provide uniform and consistent single sheet feeding. This is due in part to the ineffectiveness of the yieldable separator arrangements which are not reliable in preventing binding or feeding of multiple sheets especially when processing intermixed materials having a wide range of sizes and thicknesses.
The mixed thickness paper feeder of this invention overcomes the disadvantages of these previously known apparatus and incorporates an improved structure having a pivotally mounted endless belt conveyor for cooperative interaction with a separator rotatably driven on a shaft journaled within a fixed mounting. The conveyor is yieldably displaceable in response to a force exerted by the transported materials and is automatically compensating to provide the necessary clearance for more effectively accommodating a wide range of mixed thickness materials. The spring biasing of the conveyor additionally serves as a wear compensation feature.
Another advantage of the instant invention is the elimination of sticking of adjacently stacked materials or of a shingling effect during transportation of the materials. This is achieved in part by stacking the materials on edge, the use of a feed limiting barrier, and further by the employment of a sheet limit stop which relieves intersheet pressure and thereby reduces the compressive take-up force during the wiping contact and removal of the individual sheets from the pack.